Welcome to the SMF Family...There is tons of info on Baby Back Ribs...You may wish to start with the free 5 Day E-course. Then review the info on 2-2-1 BB Rib cooking method. Do a search on the MES 40 you bought. Search Rubs and Sauces as well. In a nut shell you have some studying to do...
Pull the membrane and Rub with what you like then Wrap in plastic the night before. Refrigerate.
Smoke at 225*F
Smoke ( 2 ) hours with wood chips. A 1/4 cup is plenty. You are looking for Thin Blue Smoke (TBS). Replenish every 30-45 minutes.
Hickory is common but somewhat strong, Apple is a great milder choice.
Wrap in Foil with a liquid like Apple Juice, or you may like my Foiling Juice. Place in the smoker for ( 2 ) hours without wood chips.
Carefully remove from the foil and go back in the smoker for ( 1) more hour with wood chips. Save the juices from the foil to mix with your sauce. Get it...2-2-1 This will get them Tender where each bite comes away from the bone easily.
If you literally want the bones to Fall Off, you will want to increase the Foiling Time by 30-60 minutes.
Stuff to look at: http://www.smokingmeatforums.com/t/80136/excessive-white-smoke
Try this... It is Mild and compliments different style sauces well...Anything else, just ask...JJ
Mild Bubba Q Rub
1/2C Sugar in the Raw (Turbinado)
2T Sweet Paprika (Hungarian)
1T Kosher Salt
1T Chili Powder (contains some Cumin and Oregano) Ancho Chile is same without cumin, oregano etc.
1T Granulated Garlic
1T Granulated Onion
1tsp Black Pepper, more if you like
1/2tsp Grnd Allspice
Cayenne or Chipotle Pwd to taste, start with 1/2tsp and go from there.
You may also like this Foiling Juice for Ribs...